speed trap

WordReference Random House Unabridged Dictionary of American English © 2026

speed′ trap′, 

1. a section of a road where hidden police, radar, etc., carefully check the speed of motorists and strictly enforce traffic regulations: sometimes characterized by hard-to-see signals, hidden traffic signs, etc.

• 1920–25

Collins Concise English Dictionary © HarperCollins Publishers::

speed trap noun

1. a section of road on which the police check the speed of vehicles, often using radar